Earlier quoted context omitted.
You have to make those opportunities to plan long-term. Once you start to form those, it will be amazing how many opportunities present themselves.
That's a contingent fact about the place and era you live in. Medieval peasants - the majority of people who have ever lived - were not dumbasses, not all of them - but there simply wasn't a way for even the smartest to accumulate long-term wealth. At best you could maybe get your neighbours to owe you a few more favours, and maybe once in a generation if you played every card right there might be a chance for a patr…
Some of these things you could make yourself or were commonly self-made instead of buying, but that, too, requires planning and discipline.
I'm a bit shocked that some people think of medieval life as something like Elbonia in Dilbert comics. Heck, I even find the middle ages a pretty boring time in human history, but I know enough to understand that it wasn't as simple as "everyone lived in the mud and ate mud".